Display device with touch detection function and electronic apparatus

ABSTRACT

According to an aspect, a display device with a touch detection function includes a display area; a pixel electrode; a plurality of scan lines; a plurality of data lines; an auxiliary wiring that is a wiring of a metal material having an electrical resistance lower than that of a material of the drive electrodes, is arranged so as to extend in the row direction for each row of the pixels, and is electrically coupled to the drive electrode; a control device that performs image display control and touch detection control; a touch detection electrode that faces the drive electrodes and forms a capacitance with the drive electrodes; and a touch detection unit that detects a position of a proximity object based on a detection signal sent from the touch detection electrode.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims priority to Japanese Priority PatentApplication JP 2014-102868 filed in the Japan Patent Office on May 16,2014, and JP 2015-095421 filed in the Japan Patent Office on May 8,2015, the entire content of which is hereby incorporated by reference.

BACKGROUND

1. Technical Field

The present invention relates to a display device capable of detectingan external proximity object, and more particularly, to a display devicewith a touch detection function capable of detecting an externalproximity object approaching from the outside based on a change in acapacitance and to an electronic apparatus.

2. Description of the Related Art

Recently, a touch detection device, which is referred to as a so-calledtouch panel, capable of detecting an external proximity object has beenattracting attention. The touch panel is used for a display device witha touch detection function which is mounted on or integrated into thedisplay device such as a liquid-crystal display device. The displaydevice with a touch detection function displays various button imagesand the like on the display device, and this allows input of informationusing the touch panel instead of normal mechanical buttons. The displaydevice with a touch detection function having such a touch panel doesnot require an input device such as a keyboard, a mouse, or a keypad.Therefore, in addition to computers, the use thereof tends to increasealso in portable information terminals such as mobile phones.

Examples of the touch detection device include an optical-type touchdetection device, a resistive-type touch detection device, and acapacitive-type touch detection device. The capacitive-type touchdetection device used for a mobile terminal or so has a comparativelysimple structure and is capable of achieving low power consumption. Forexample, Japanese Patent No. 5439060 (JP-5439060) describes a capacitivetouch panel.

Japanese Patent Application Laid-open Publication No. 2012-22148(JP-A-2012-22148) describes pixels in each of which sub-pixelsrepresenting the same color are arrayed in a direction along a scanline.

When the display device with a touch detection function described inJP-5439060 is to be applied to the display device described inJP-A-2012-22148, resistance of a drive electrode that supplies a drivesignal affects a time constant of a waveform of the drive signal, andthis may therefore exert an influence on the accuracy of touchdetection. For this reason, an auxiliary wiring having a low resistancemay be added in order to reduce a connection resistance. However,because the auxiliary wiring of a metal material is less translucentthan a material of the drive electrode, an aperture ratio may becomeless due to the restriction of the array of the sub-pixels described inJP-A-2012-22148.

For the foregoing reasons, there is a need for a display device with atouch detection function and an electronic apparatus that can reduce aninfluence on an aperture ratio and improve accuracy of touch detection.

For the foregoing reasons, there is a need for a display device with atouch detection function and an electronic apparatus that can reduce aconnection resistance of a selection switch for selecting a driveelectrode to be supplied with a drive signal, and can narrow a frame.

SUMMARY

According to an aspect, a display device with a touch detection functionincludes a display area that has a plurality of pixels arranged in amatrix including a plurality of rows and a plurality of columns, inwhich one of the pixels includes a plurality of sub-pixels thatrepresent mutually different colors and are arrayed in one column with krows (k is a natural number of 3 or more), and in which arbitrarysub-pixels representing same color among arbitrary pixels that areadjacent to each other in a row direction are arrayed along the rowdirection; a display function layer that has an image display functionfor displaying an image in the display area; a pixel electrode that isprovided in each of the sub-pixels and supplies an applied voltage tothe display function layer by a potential difference with a commonpotential which is a reference; a plurality of scan lines that extend inthe row direction of the display area and scan switching elements of thesub-pixels; a plurality of data lines that extend in a column directionof the display area and supply an applied voltage to the pixelelectrodes; a plurality of drive electrodes that are provided facing thepixel electrodes and extend in the row direction; an auxiliary wiringthat is a wiring of a metal material having an electrical resistancelower than that of a material of the drive electrodes, is arranged so asto extend in the row direction for each row of the pixels, and iselectrically coupled to the drive electrode; a control device thatperforms image display control so as to apply the common potential tothe drive electrodes based on an image signal to achieve the imagedisplay function of the display function layer, and that performs touchdetection control so as to supply a drive signal for touch to the driveelectrodes; a touch detection electrode that faces the drive electrodesand forms a capacitance with the drive electrodes; and a touch detectionunit that detects a position of a proximity object based on a detectionsignal sent from the touch detection electrode.

According to another aspect, an electronic apparatus includes thedisplay device with a touch detection function.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram of a configuration example of a display devicewith a touch detection function according to an embodiment;

FIG. 2 is an explanatory diagram illustrating a state where no finger isin contact with or in proximity to a device for explanation of the basicprinciple of capacitive-type touch detection;

FIG. 3 is an explanatory diagram of an example of an equivalent circuitin the state where no finger is in contact with or in proximity to adevice illustrated in FIG. 2;

FIG. 4 is an explanatory diagram illustrating a state where a finger isin contact with or in proximity to a device for explanation of the basicprinciple of a capacitive-type touch detection method;

FIG. 5 is an explanatory diagram of an example of the equivalent circuitin the state where the finger is in contact with or in proximity to adevice illustrated in FIG. 4;

FIG. 6 is a diagram of an example of waveforms of a drive signal and atouch detection signal;

FIG. 7 is a diagram of an example of a module on which the displaydevice with a touch detection function according to the presentembodiment is mounted;

FIG. 8 is a cross-sectional view of a schematic cross-section structureof a display unit with a touch detection function according to thepresent embodiment;

FIG. 9 is a diagram of an example of a control device for the displaydevice with a touch detection function according to the presentembodiment;

FIG. 10 is a circuit diagram of a pixel array of the display unit with atouch detection function according to the present embodiment;

FIG. 11 is a perspective view of a configuration example of driveelectrodes and touch detection electrodes of the display unit with atouch detection function according to the present embodiment;

FIG. 12 is a schematic diagram of an operation example of touchdetection in the display device with a touch detection functionaccording to the present embodiment;

FIG. 13 is a schematic diagram of an operation example of the touchdetection in the display device with a touch detection functionaccording to the present embodiment;

FIG. 14 is a schematic diagram of an operation example of the touchdetection in the display device with a touch detection functionaccording to the present embodiment;

FIG. 15 is an explanatory diagram for explaining an operation of adisplay and touch detection in the display device with a touch detectionfunction according to the present embodiment;

FIG. 16 is an explanatory diagram for explaining a positional relationbetween a pixel and an auxiliary wiring according to the presentembodiment;

FIG. 17 is an explanatory diagram for explaining a relationship amongdrive electrodes, drive electrode pieces, slits, and auxiliary wiringsaccording to the present embodiment;

FIG. 18 is an explanatory diagram for explaining a relationship amongdrive electrodes, drive electrode pieces, slits, and auxiliary wiringsaccording to the present embodiment;

FIG. 19 is a schematic diagram of a cross section schematicallyillustrating an A-B cross section of a pixel substrate illustrated inFIG. 16;

FIG. 20 is a schematic diagram of a cross section schematicallyillustrating a C-D cross section of the pixel substrate illustrated inFIG. 16;

FIG. 21 is an explanatory diagram representing a pixel array accordingto a modification of the present embodiment;

FIG. 22 is an explanatory diagram representing a pixel array accordingto a modification of the present embodiment;

FIG. 23 is a diagram of an example of an electronic apparatus to whichthe display device with a touch detection function according to thepresent embodiment is applied;

FIG. 24 is a diagram of an example of the electronic apparatus to whichthe display device with a touch detection function according to thepresent embodiment is applied; and

FIG. 25 is a diagram of an example of an electronic apparatus to whichthe display device with a touch detection function according to thepresent embodiment is applied.

DETAILED DESCRIPTION

Exemplary embodiments for implementing the present invention will beexplained in detail below with reference to the accompanying drawings.The present invention is not limited by the contents described in thefollowing embodiments. In addition, the components described as followsinclude those which can be easily thought of by persons skilled in theart and those which are substantially equivalent to each other.Moreover, the components described as follows can be arbitrarilycombined with each other. The disclosure is only an example, andtherefore modifications within the gist of the invention which can bereadily thought of by persons skilled in the art are obviously includedin the scope of the present invention. Moreover, the widths, thethicknesses, the shapes, and the like of units in the drawings may beschematically represented as compared with those of actual aspects forthe sake of clearer description. However, these representations are onlyexamples, and therefore the interpretation of the present invention isnot limited thereby. In the present specification and the figures, thesame signs are assigned to the same elements as those in alreadydescribed figures, and detailed explanation may be omitted from time totime.

FIG. 1 is a block diagram of a configuration example of a display devicewith a touch detection function according to an embodiment. A displaydevice 1 with a touch detection function includes a display unit 10 witha touch detection function, a control unit 11, a gate driver 12, asource driver 13, a source selector 13S, a drive electrode driver 14,and a touch detection unit 40. The display device 1 with a touchdetection function is a display device in which the display unit 10 witha touch detection function has a built-in touch detection function. Thedisplay unit 10 with a touch detection function is a so-called in-celltype device in which a liquid-crystal display unit 20 using a liquidcrystal element as a display element and a capacitive-type touchdetection device 30 are integrated. The display unit 10 with a touchdetection function may be a so-called on-cell type device in which thecapacitive-type touch detection device 30 is mounted on theliquid-crystal display unit 20 that uses a liquid crystal element as adisplay element.

The liquid-crystal display unit 20 is a device that sequentially scansand displays horizontal lines one by one according to a scan signalVscan supplied from the gate driver 12, as explained later. The controlunit 11 is a circuit that controls so as to supply a control signal tothe gate driver 12, the source driver 13, the drive electrode driver 14,and the touch detection unit 40 based on a video signal Vdisp suppliedfrom an external device, and so that these units operate insynchronization with one another. The control device according to thepresent invention includes the control unit 11, the gate driver 12, thesource driver 13, and the drive electrode driver 14.

The gate driver 12 has a function of sequentially selecting onehorizontal line as a target of display driving of the display unit 10with a touch detection function, based on the control signal suppliedfrom the control unit 11.

The source driver 13 is a circuit that supplies a pixel signal Vpix toeach pixel Pix (sub-pixels SPix), explained later, of the display unit10 with a touch detection function based on the control signal suppliedfrom the control unit 11. As explained later, the source driver 13generates a pixel signal, in which the pixel signal Vpix for a pluralityof sub-pixels SPix in the liquid crystal display unit 20 istime-division multiplexed, from the video signal Vdisp for onehorizontal line, and supplies the generated pixel signal to the sourceselector 13S. The source driver 13 also generates a switch controlsignal Vsel required to divide the pixel signal Vpix multiplexed on animage signal Vsig therefrom, and supplies the generated switch controlsignal along with the pixel signal Vpix to the source selector 13S. Thesource selector 13S enables reduction in the number of wirings betweenthe source driver 13 and the control unit 11.

The drive electrode driver 14 is a circuit that supplies a drive signalfor touch detection (drive signal for touch; hereinafter, “drive signal”or “touch drive signal”) VcomAC and a drive voltage for display(hereinafter, “drive voltage” or “display drive voltage”) VcomDC being avoltage for display to a drive electrode COML, which are explainedlater, of the display unit 10 with a touch detection function based onthe control signal supplied from the control unit 11.

The touch detection unit 40 is a circuit that detects the presence orabsence of a touch (contact state, explained later) performed on thetouch detection device 30 based on the control signal supplied from thecontrol unit 11 and a touch detection signal Vdet supplied from thetouch detection device 30 of the display unit 10 with a touch detectionfunction, and that calculates coordinates and the like of the touch in atouch detection area when the presence of a touch is detected. The touchdetection unit 40 includes a touch detection signal amplifier 42, ananalog-to-digital (A/D) convertor 43, a signal processing unit 44, acoordinate extracting unit 45, and a detection-timing control unit 46.

The touch detection signal amplifier 42 amplifies the touch detectionsignal Vdet supplied from the touch detection device 30. The touchdetection signal amplifier 42 may include a low-pass analog filter thatremoves a high frequency component (noise component) contained in thetouch detection signal Vdet, extracts touch components, and outputs thetouch components.

Basic Principle of Capacitive-Type Touch Detection

The touch detection device 30 operates based on the basic principle ofcapacitive-type touch detection, and outputs the touch detection signalVdet. The basic principle of the touch detection in the display device 1with a touch detection function according to the present embodiment willbe explained below with reference to FIG. 1 to FIG. 6. FIG. 2 is anexplanatory diagram illustrating a state where no finger is in contactwith or in proximity to a device for explanation of the basic principleof the capacitive-type touch detection. FIG. 3 is an explanatory diagramof an example of an equivalent circuit in the state where no finger isin contact with or in proximity to a device illustrated in FIG. 2. FIG.4 is an explanatory diagram illustrating a state where a finger is incontact with or in proximity to a device for explanation of the basicprinciple of the capacitive-type touch detection. FIG. 5 is anexplanatory diagram of an example of the equivalent circuit in the statewhere the finger is in contact with or in proximity to a deviceillustrated in FIG. 4. FIG. 6 is a diagram of an example of waveforms ofa drive signal and a touch detection signal. In the followingexplanation, a proximity object explained as the finger is not limitedto the finger, and a pen type tool or the like may be used.

For example, as illustrated in FIG. 2, a capacitive element C1 includesa pair of electrodes, a drive electrode E1 and a touch detectionelectrode E2, which are arranged opposite to each other across adielectric body D. As illustrated in FIG. 3, the capacitive element C1is coupled at its one end to an alternating-current (AC) signal source(drive signal source) S and is coupled at the other end to a voltagedetector (touch detection unit) DET. The voltage detector DET is anintegration circuit included in, for example, the touch detection signalamplifier 42 illustrated in FIG. 1.

When an AC square wave Sg of a predetermined frequency (e.g., aboutseveral kHz to several hundreds of kHz) is applied from the AC signalsource S to the drive electrode E1 (one end of the capacitive elementC1), an output waveform (touch detection signal Vdet) appears via thevoltage detector DET coupled to the touch detection electrode E2 (theother end of the capacitive element C1). The AC square wave Sgcorresponds to the drive signal VcomAC explained later.

In the state where no finger is in contact with (or in proximity to) adevice (a non-contact state), a current I₀ according to the capacitanceof the capacitive element C1 flows in association with charge anddischarge to the capacitive element C1 as illustrated in FIG. 2 and FIG.3. The voltage detector DET illustrated in FIG. 3 converts thefluctuation of the current I₀ according to the AC square wave Sg intothe fluctuation of a voltage (waveform V₀ indicated by solid line inFIG. 6).

On the other hand, in the state where the finger is in contact with (orin proximity to) a device (a contact state), as illustrated in FIG. 4, acapacitance C2 formed by the finger is in contact with or in proximityto the touch detection electrode E2, and a capacitance for a fringebetween the drive electrode E1 and the touch detection electrode E2 isthereby blocked to act as a capacitive element C1′ having a capacitancesmaller than that of the capacitive element C1. It is understood fromthe equivalent circuit illustrated in FIG. 5 that a current I₁ flows inthe capacitive element C1′. As illustrated in FIG. 6, the voltagedetector DET converts the fluctuation of the current I₁ according to theAC square wave Sg into the fluctuation of a voltage (waveform V₁indicated by dotted line). In this case, the amplitude of the waveformV₁ becomes lower as compared with that of the waveform V₀. Thereby, anabsolute value |ΔV| of a voltage difference between the waveform V₀ andthe waveform V₁ changes according to the influence of an objectapproaching from the outside such as a finger. To accurately detect theabsolute value |ΔV| of the voltage difference between the waveform V₀and the waveform V₁, it is more preferable that the voltage detector DEToperates by providing periods Reset in which charge and discharge of thecapacitor are reset in synchronization with the frequency of the ACsquare wave Sg through switching in the circuit.

The touch detection device 30 illustrated in FIG. 1 is configured tosequentially scan detection blocks one by one and perform touchdetection according to a drive signal Vcom (drive signal VcomAC,explained later) supplied from the drive electrode driver 14.

The touch detection device 30 is configured to output the touchdetection signal Vdet for each detection block from a plurality of touchdetection electrodes TDL, explained later, via the voltage detector DETillustrated in FIG. 3 or FIG. 5 to be supplied to the A/D convertor 43of the touch detection unit 40.

The A/D convertor 43 is a circuit that samples each analog signal outputfrom the touch detection signal amplifier 42 at a timing synchronizedwith the drive signal VcomAC and converts the sampled signal into adigital signal.

The signal processing unit 44 includes a digital filter that reduces anyfrequency component (noise component), included in the output signal ofthe A/D convertor 43, other than the frequency at which the drive signalVcomAC is sampled. The signal processing unit 44 is a logic circuit thatdetects the presence or absence of a touch performed on the touchdetection device 30 based on the output signal of the A/D convertor 43.The signal processing unit 44 performs processing of extracting only adifference of the voltages caused by the finger. The difference of thevoltages caused by the finger is the absolute value |ΔV| of thedifference between the waveform V₀ and the waveform V₁. The signalprocessing unit 44 may perform an operation of averaging absolute values|ΔV| per one detection block to calculate an average value of theabsolute values |ΔV|. This enables the signal processing unit 44 toreduce the influence caused by the noise. The signal processing unit 44compares the detected difference of the voltages caused by the fingerwith a predetermined threshold voltage, and determines, if thedifference of the voltages is the threshold voltage or more, that theexternal proximity object is in the contact state. Meanwhile, if thedifference of the voltages is less than the threshold voltage, thesignal processing unit 44 determines that the external proximity objectis in the non-contact state. In this way, the touch detection unit 40enables touch detection.

The coordinate extracting unit 45 is a logic circuit that calculates,when the signal processing unit 44 detects a touch, touch panelcoordinates of the touch, and outputs the touch panel coordinates as asignal output Vout. The detection-timing control unit 46 synchronizesthe A/D convertor 43 and the signal processing unit 44.

Module

FIG. 7 is a diagram of an example of a module on which the displaydevice with a touch detection function according to the presentembodiment is mounted. As illustrated in FIG. 7, the display device 1with a touch detection includes a pixel substrate 2 (translucentsubstrate 21) and a flexible printed board T, which are explained later.The pixel substrate 2 is provided with Chip On Glass (COG) 19, and has adisplay area Ad of the liquid crystal display unit 20 and a frame Gdformed thereon. The COG 19 is a driver IC (integrated circuit) chipmounted on the pixel substrate 2 and is a control device with built-incircuits, such as the control unit 11 and the source driver 13illustrated in FIG. 1, required for a display operation. In the presentembodiment, the source driver 13 and the source selector 13S are formedon the pixel substrate 2. The source driver 13 and the source selector13S may be built into the COG 19. The drive electrode driver 14 is builtin the COG 19. The gate driver 12 is formed on the pixel substrate 2 asgate drivers 12A and 12B.

As illustrated in FIG. 7, a drive electrode block DB of the driveelectrode COML and the touch detection electrode TDL are formed so as tothree-dimensionally intersect each other in a direction perpendicular tothe surface of the pixel substrate 2.

The drive electrodes COML are divided into a plurality of stripe-shapedelectrode patterns extending along one direction. When a touch detectionoperation is performed, the drive electrode driver 14 sequentiallysupplies the drive signal VcomAC to each of the electrode patterns. Thestripe-shaped electrode patterns of the drive electrodes COMLsimultaneously supplied with the drive signal VcomAC represent the driveelectrode block DB illustrated in FIG. 7. The drive electrode block DB(drive electrode COML) is formed along a long-side direction of thedisplay unit 10 with a touch detection function, and the touch detectionelectrode TDL, explained later, is formed along a short-side directionof the display unit 10 with a touch detection function. An output end ofthe touch detection electrode TDL is provided on the short-side side ofthe display unit 10 with a touch detection function and is coupled tothe touch detection unit 40 mounted on the flexible printed board T viathe flexible printed board T. In this way, the touch detection unit 40is mounted on the flexible printed board T and is coupled to each of thetouch detection electrodes TDL arranged in parallel. The flexibleprinted board T may be any terminal and is not therefore limited to theflexible printed board, and, in this case, the touch detection unit 40is provided outside the module.

The source selector 13S is formed near the display area Ad on the pixelsubstrate 2 using a thin film transistor (TFT) element. A large numberof pixels Pix, explained later, are arranged in a matrix (in the form ofrows and columns) in the display area Ad. The frames Gd and Gd are areaswhere no pixels Pix are arranged when the surface of the pixel substrate2 is viewed from the direction perpendicular thereto.

The gate driver 12 includes the gate drivers 12A and 12B and is formedon the pixel substrate 2 using the TFT element. The gate drivers 12A and12B are configured so as to be capable of driving the display area Adfrom both sides of the display area Ad where the sub-pixels SPix(pixels), explained later, are arranged in a matrix. In the followingexplanation, the gate driver 12A is described as a first gate driver 12Aand the gate driver 12B is described as a second gate driver 12B. Scanlines GCL, which are explained later, are arranged between the firstgate driver 12A and the second gate driver 12B. Therefore, the scanlines GCL explained later are provided so as to extend along a directionparallel to the extending direction of the drive electrodes COML in thedirection perpendicular to the surface of the pixel substrate 2.

The drive electrode driver 14 supplies power to the drive electrodeblock DB via a potential supply wiring. In other words, the driveelectrode block DB is supplied with the display drive voltage VcomDC viapotential supply wirings PL, and is also supplied with the drive signalVcomAC via the potential supply wirings PL. The potential supply wiringsPL are wirings formed of a conductive metal material, routed in theframes Gd and Gd. Each of the drive electrode blocks DB arranged inparallel is then driven from its both sides. The potential supply wiringPL supplying the display drive voltage VcomDC and the potential supplywiring PL supplying the drive signal VcomAC are the same wirings;however, these wirings may be provided as separate wirings.

The display device 1 with a touch detection function illustrated in FIG.7 outputs the touch detection signals Vdet from the short-side side ofthe display unit 10 with a touch detection function. This makes easierthe routing of the wirings, in the display device 1 with a touchdetection function, which are coupled to the touch detection unit 40 viathe flexible printed board T serving as a terminal unit.

Display Unit with Touch Detection Function

A configuration example of the display unit 10 with a touch detectionfunction will be explained in detail next. FIG. 8 is a cross-sectionalview of a schematic cross-section structure of the display unit with atouch detection function according to the present embodiment. FIG. 9 isa diagram of an example of the control device for the display devicewith a touch detection function according to the present embodiment.FIG. 10 is a circuit diagram of a pixel array of the display unit with atouch detection function according to the present embodiment.

As illustrated in FIG. 8, the display unit 10 with a touch detectionfunction includes the pixel substrate 2, a counter substrate 3 arrangedfacing the pixel substrate 2 in the direction perpendicular to thesurface of the pixel substrate 2, and a liquid crystal layer 6 insertedbetween the pixel substrate 2 and the counter substrate 3.

The liquid crystal layer 6 modulates the light passing therethroughaccording to the state of the electric field, and is driven in ahorizontal electric field mode such as fringe field switching (FFS) orin-plane switching (IPS). An orientation film may be provided betweenthe liquid crystal layer 6 and the pixel substrate 2 and between theliquid crystal layer 6 and the counter substrate 3 illustrated in FIG.8.

The counter substrate 3 includes a glass substrate 31 and a color filter32 formed on one face of the glass substrate 31. The touch detectionelectrodes TDL being detection electrodes of the touch detection device30 are formed on the other face of the glass substrate 31, and apolarizer 35 is further disposed on the touch detection electrodes TDL.

The pixel substrate 2 includes the translucent substrate 21 as a circuitboard, a plurality of pixel electrodes 22 arranged in a matrix on thetranslucent substrate 21, a plurality of drive electrodes COML formedbetween the translucent substrate 21 and the pixel electrodes 22, and aninsulating layer 24 that insulates the pixel electrodes 22 and the driveelectrodes COML. The drive electrodes COML are electrodes for supplying“common potential” being a reference to a plurality of pixels Pix(explained later). The drive electrode COML functions as a common driveelectrode for a liquid crystal display operation and also functions as adrive electrode for a touch detection operation. The insulating layer 24is formed on the drive electrodes COML, and the pixel electrodes 22 areformed thereon. The pixel electrodes 22 are electrodes for supplying apixel signal for display, and has translucency. The drive electrodesCOML and the pixel electrodes 22 are formed of, for example, indium tinoxide (ITO).

The counter substrate 3 includes the glass substrate 31, the colorfilter 32, and the touch detection electrodes TDL. The color filter 32is formed on one face of the glass substrate 31. The color filter 32 isconfigured to periodically array color filter layers in three colors of,for example, red (R), green (G), and blue (B), and a set of the threecolors of R, G, and B is associated with each of display pixels. Thetouch detection electrodes TDL are formed on the other face of the glasssubstrate 31. The touch detection electrodes TDL are electrodes formedof, for example, ITO and having translucency. The polarizer 35 isdisposed on the touch detection electrodes TDL.

The liquid crystal layer 6 functions as a display function layer andmodulates the light passing therethrough according to the state of anelectric field. The electric field is formed by a potential differencebetween a voltage of the drive electrodes COML and a voltage of thepixel electrodes 22. The liquid crystal of the liquid crystal layer 6 isdriven in the horizontal electric field mode such as FFS or IPS.

The orientation film is provided respectively between the liquid crystallayer 6 and the pixel substrate 2 and between the liquid crystal layer 6and the counter substrate 3, and an incident-side polarizer is disposedon the bottom side of the pixel substrate 2. However, these units areomitted herein from the figures.

System Configuration Example of Display Device

The pixel substrate 2 includes the display area Ad, the COG 19 havingfunctions of an interface (I/F) and a timing generator, the first gatedriver 12A, the second gate driver 12B, and the source driver 13, whichare provided on the translucent substrate 21. The flexible printed boardT illustrated in FIG. 7 transmits an external signal to the COG 19illustrated in FIG. 7 and FIG. 9 or a drive power for driving the COG 19thereto. The pixel substrate 2 includes the display area Ad which isprovided on the surface of the translucent substrate 21 of a translucentinsulating substrate (e.g. a glass substrate) and on which a number ofpixels including liquid crystal cells are arranged in a matrix (in theform of rows and columns), the source driver (horizontal drive circuit)13, and the gate drivers (vertical drive circuits) 12A and 12B. The gatedrivers (vertical drive circuits) 12A and 12B are arranged so as tosandwich the display area Ad therebetween, as the first gate driver 12Aand the second gate driver 12B.

The display area Ad has a matrix (in the form of rows and columns)structure in which the sub-pixels SPix including the liquid crystallayer are arranged in m rows×n columns. In this specification, the rowindicates a pixel row having n pieces of sub-pixels SPix arrayed in onedirection. The column indicates a pixel column having m pieces ofsub-pixels SPix arrayed in a direction perpendicular to the direction inwhich the rows are arrayed. The values of m and n are determinedaccording to a vertical display resolution and a horizontal displayresolution respectively. In the display area Ad, each of scan linesGCL_(m+1), GCL_(m−2), GCL_(m+). . . is arranged in each row and each ofdata lines SGL_(n+1), SGL_(n+2), SGL_(n+3), SGL_(n+4), SGL_(n+5) . . .is arranged in each column with respect to an m-row/n-column array ofthe sub-pixels SPix. In the embodiment, the scan lines GCL_(m+1),GCL_(m+2), GCL_(m+3) . . . may be hereinafter described as scan linesGCL as a representative thereof, and the data lines SGL_(n+1),SGL_(n+2), SGL_(n+3), SGL_(n+4), SGL_(n+5) . . . may be hereinafterdescribed as data lines SGL as a representative thereof.

A master clock, a horizontal synchronization signal, and a verticalsynchronization signal, which are external signals input from anexternal device, are input to the pixel substrate 2 to be supplied tothe COG 19. The COG 19 performs level conversion (boosting) of themaster clock, the horizontal synchronization signal, and the verticalsynchronization signal, each of which has a voltage magnitude of anexternal power supply, to a voltage magnitude of an internal powersupply required for driving the liquid crystal, passes thelevel-converted master clock, horizontal synchronization signal, andvertical synchronization signal through the timing generator, andgenerates a vertical start pulse VST, a vertical clock pulse VCK, ahorizontal start pulse HST, and a horizontal clock pulse HCK. The COG 19supplies the vertical start pulse VST and the vertical clock pulse VCKto the first gate driver 12A and the second gate driver 12B, and alsosupplies the horizontal start pulse HST and the horizontal clock pulseHCK to the source driver 13. The COG 19 generates a drive voltage fordisplay (counter electrode potential) VCOM which is called a commonpotential and is commonly supplied to pixels with respect to the pixelelectrode for each sub-pixel SPix, and supplies the generated commonpotential to the drive electrodes COML.

The first gate driver 12A and the second gate driver 12B include a shiftregister, explained later, and may further include a latch circuit andthe like. The first gate driver 12A and the second gate driver 12B aresupplied with the vertical start pulse VST, and the latch circuit isthereby synchronized with the vertical clock pulse VCK to sequentiallysample and latch the display data output from the COG 19 in onehorizontal period. The first gate driver 12A and the second gate driver12B sequentially output the digital data for one line latched in thelatch circuit as a vertical scan pulse, and supply the digital data tothe scan lines GCL, to thereby sequentially select sub-pixels SPix rowby row. The first gate driver 12A and the second gate driver 12B arearranged along the extending direction of the scan lines GCL so as tosandwich the scan lines GCL therebetween. The first gate driver 12A andthe second gate driver 12B sequentially output the digital data in theorder from an upper side of the display area Ad i.e. from an upperdirection of vertical scanning to a lower side of the display area Adi.e. to a lower direction of the vertical scanning.

The source driver 13 is supplied with, for example, 6-bit R (red), G(green), and B (blue) image signals Vsig. The source driver 13 writesdisplay data to sub-pixels SPix of a row selected through verticalscanning performed by the first gate driver 12A and the second gatedriver 12B for each pixel, or for each pixel group including a pluralityof pixels, or for all pixels at a time via the data lines SGL.

Formed on the translucent substrate 21 are wirings such as switchingelements Tr of the sub-pixels SPix illustrated in FIG. 9 and FIG. 10,the data lines SGL for supplying a pixel signal Vpix to the pixelelectrodes 22 illustrated in FIG. 8, and the scan lines GCL for drivingthe switching elements Tr. In this way, the data lines SGL are extendedalong a plane parallel to the surface of the translucent substrate 21,and supply the pixel signal Vpix for displaying an image to the pixels.The liquid crystal display unit 20 illustrated in FIG. 10 has thesub-pixels SPix arrayed in the matrix. The sub-pixel SPix includes theswitching element Tr and a liquid crystal capacitor LC of the liquidcrystal layer. The switching element Tr is an element such as TFT, whichis formed of an n-channel metal oxide semiconductor (MOS) TFT having anamorphous silicon semiconductor layer in this example. A source of theswitching element Tr is coupled to the data line SGL, a gate thereof iscoupled to the scan line GCL, and a drain thereof is coupled to one endof the liquid crystal capacitor LC. The liquid crystal capacitor LC iscoupled at its one end to the drain of the switching element Tr, and iscoupled at the other end to the drive electrode COML.

The first gate driver 12A and the second gate driver 12B illustrated inFIG. 9 apply a vertical scan pulse to the gates of the switchingelements Tr of the sub-pixels SPix through the scan lines GCLillustrated in FIG. 10 to thereby sequentially select one row (onehorizontal line), as a target of display driving, from among thesub-pixels SPix formed in the matrix in the display area Ad. The sourcedriver 13 supplies the pixel signal Vpix to each of the sub-pixels SPixincluded in one horizontal line sequentially selected by the first gatedriver 12A and the second gate driver 12B through the data lines SGL. Inthe sub-pixels SPix, one horizontal line is displayed according to thesupplied pixel signal. The drive electrode driver 14 applies the drivesignal for display (display drive voltage VcomDC) to drive the driveelectrodes COML.

As explained above, the display device 1 with a touch detection functiondrives the first gate driver 12A and the second gate driver 12B so as tosequentially scan the scan lines GCL_(m+1), GCL_(m+2), and GCL_(m+3),and one horizontal line is thereby sequentially selected. The displaydevice 1 with a touch detection function causes the source driver 13 tosupply a pixel signal to the sub-pixels SPix belonging to one horizontalline, and thereby displays the horizontal lines one by one. Whenperforming the display operation, the drive electrode driver 14 appliesthe drive signal Vcom to the drive electrode COML corresponding to theselected one horizontal line.

The color filter 32 illustrated in FIG. 8 is structured to periodicallyarray color regions of the color filter colored in three colors of, forexample, red (R), green (G), and blue (B), and to associate colorregions 32R, 32G, and 32B (see FIG. 10) of the three colors of R, G, andB, which are grouped in a set as a pixel Pix, with the sub-pixels SPixillustrated in FIG. 10. The color filter 32 faces the liquid crystallayer 6 in the direction perpendicular to the translucent substrate 21.The color filter 32 may be a combination of other colors if the colorregions are colored in different colors.

A sub-pixel SPix illustrated in FIG. 10 is coupled to the othersub-pixels SPix belonging to the same row in the liquid crystal displayunit 20 through the scan line GCL. The scan lines GCL are coupled to thegate driver 12 and are supplied with the scan signal Vscan from the gatedriver 12. A sub-pixel SPix is coupled to the other sub-pixels SPixbelonging to the same column in the liquid crystal display unit 20through the data line SGL. The data lines SGL are coupled to the sourcedriver 13 and are supplied with the pixel signal Vpix from the sourcedriver 13.

A sub-pixel SPix is coupled to the other sub-pixels SPix belonging tothe same row in the liquid crystal display unit 20 through the driveelectrode COML. The drive electrode COML is coupled to the driveelectrode driver 14 and is supplied with the display drive voltageVcomDC from the drive electrode driver 14. In other words, in thisexample, the sub-pixels SPix belonging to the same row share the driveelectrode COML.

The gate driver 12 illustrated in FIG. 1 applies the scan signal Vscanto the gates of the switching elements Tr in the sub-pixels SPix throughthe scan line GCL illustrated in FIG. 10 to thereby sequentially selectone row (one horizontal line), as a target of display driving, fromamong the sub-pixels SPix formed in the matrix in the liquid crystaldisplay unit 20. The source driver 13 illustrated in FIG. 1 supplies thepixel signals Vpix to the sub-pixels SPix forming one horizontal linesequentially selected by the gate driver 12 through the respective datalines SGL illustrated in FIG. 10. In the sub-pixels SPix, one horizontalline is displayed according to the supplied pixel signals Vpix. Thedrive electrode driver 14 illustrated in FIG. 1 applies the drivesignals Vcom to the drive electrodes COML to drive the drive electrodesCOML in each drive electrode block DB including a predetermined numberof drive electrodes COML as illustrated in FIG. 7 and FIG. 9.

As explained above, the liquid crystal display unit 20 drives the gatedriver 12 so as to time-divisionally and sequentially scan the scanlines GCL, and one horizontal line is thereby sequentially selected. Inthe liquid crystal display unit 20, the source driver 13 supplies thepixel signals Vpix to the sub-pixels SPix belonging to the onehorizontal line, and the horizontal line is thereby displayed one byone. When performing the display operation, the drive electrode driver14 applies the display drive voltage VcomDC to the drive electrode blockDB including the drive electrodes COML each corresponding to the onehorizontal line.

The drive electrode COML according to the present embodiment functionsas a drive electrode of the liquid crystal display unit 20 and alsofunctions as a drive electrode of the touch detection device 30. FIG. 11is a perspective view of a configuration example of drive electrodes andtouch detection electrodes of the display unit with a touch detectionfunction according to the present embodiment. The drive electrodes COMLillustrated in FIG. 11 face the pixel electrodes 22 in the directionperpendicular to the surface of the translucent substrate 21 asillustrated in FIG. 8. The touch detection device 30 includes the driveelectrodes COML provided in the pixel substrate 2 and the touchdetection electrodes TDL provided in the counter substrate 3. The touchdetection electrodes TDL are formed from stripe-shaped electrodepatterns extending along a direction intersecting an extending directionof the electrode patterns of the drive electrodes COML. The touchdetection electrodes TDL face the drive electrodes COML in the directionperpendicular to the surface of the translucent substrate 21. Eachelectrode pattern of the touch detection electrodes TDL is coupled to aninput of the touch detection signal amplifier 42 of the touch detectionunit 40. The electrode pattern in which the drive electrode COML and thetouch detection electrode TDL intersect each other produces acapacitance at the intersection. The touch detection electrodes TDL orthe drive electrodes COML (drive electrode block DB) are not limited tothe stripe shape in which a plurality of stripes are separated from eachother. For example, the touch detection electrodes TDL or the driveelectrodes COML (drive electrode block DB) may be comb-shaped.Alternatively, the touch detection electrodes TDL or the driveelectrodes COML (drive electrode block DB) have only to be separatedfrom each other, and therefore the shape of each slit that separates thedrive electrodes COML may be a straight line or a curve line.

With this structure, when a touch detection operation is performed inthe touch detection device 30, the drive electrode driver 14 drives thedrive electrode blocks DB so as to time-divisionally andline-sequentially scan the drive electrode blocks DB illustrated in FIG.7. Thereby, the drive electrode block DB (one detection block) of thedrive electrodes COML is sequentially selected in a scan direction Scan.The touch detection device 30 then outputs the touch detection signalVdet from each of the touch detection electrodes TDL. In this way, thetouch detection device 30 is configured so as to perform the touchdetection on the one detection block.

FIG. 12, FIG. 13, and FIG. 14 are schematic diagrams of an operationexample of the touch detection in the display device with a touchdetection function according to the present embodiment. FIG. 15 is anexplanatory diagram for explaining a display and an operation of touchdetection in the display device with a touch detection functionaccording to the present embodiment. When the drive electrode block DBof the drive electrodes COML illustrated in FIG. 7 are 20 driveelectrode blocks DB1 to DB20, these figures represent an applicationoperation of the touch drive signal VcomAC to each of the driveelectrode blocks DB1 to DB20. A drive signal applied block DBACrepresents the drive electrode block DB to which the touch drive signalVcomAC is applied, and the other drive electrode blocks DB are notapplied with a voltage to be in a state in which the potential is notfixed, in a so-called floating state. The drive signal applied blockDBAC indicates the drive electrode block DB applied with the touch drivesignal VcomAC, and the display drive voltage VcomDC is applied may bethe other drive electrode blocks DB so that the potential may be fixed.The drive electrode driver 14 illustrated in FIG. 1 selects the driveelectrode block DB3 from among the drive electrode blocks DB as a targetof touch detection operation illustrated in FIG. 12, and applies thetouch drive signal VcomAC thereto. Next, the drive electrode driver 14selects the drive electrode block DB4 from among the drive electrodeblocks DB illustrated in FIG. 13, and applies the touch drive signalVcomAC thereto. The drive electrode driver 14 then selects the driveelectrode block DB5 from among the drive electrode blocks DB illustratedin FIG. 14, and applies the touch drive signal VcomAC thereto. In thisway, the drive electrode driver 14 sequentially selects the driveelectrode block DB, applies the touch drive signal VcomAC thereto, andscans over the entire drive electrode blocks DB. The number of the driveelectrode blocks DB is not limited to 20.

In the touch detection device 30, one of the drive electrode blocks DBillustrated in FIG. 12 to FIG. 14 corresponds to the drive electrode E1based on the basic principle of the capacitive-type touch detection. Oneof the touch detection electrodes TDL in the touch detection device 30corresponds to the touch detection electrode E2. The touch detectiondevice 30 is configured to detect a touch according to the basicprinciple. As illustrated in FIG. 11, by mutually three-dimensionallyintersecting electrode patterns, capacitive-type touch sensors areformed into a matrix. Therefore, by scanning over the entire touchdetection surface of the touch detection device 30, a position where anexternal proximity object comes in contact with or is in proximity tothe touch detection surface can also be detected.

As illustrated in FIG. 15, the control unit 11 controls so as to supplya control signal to the gate driver 12, the source driver 13, the driveelectrode driver 14, and the touch detection unit 40 based on anexternally supplied video signal Vdisp and so that these units operatein synchronization with one another. The gate driver 12 supplies thescan signal Vscan to the liquid-crystal display unit 20 in a displayoperation period Pd illustrated in FIG. 15, and sequentially selects onehorizontal line as a target of display driving. The source driver 13 andthe source selector 13S supply the pixel signals Vpix to the pixels Pixthat form one horizontal line selected by the gate driver 12 in thedisplay operation period Pd.

The drive electrode driver 14 applies the display drive voltage VcomDCto the drive electrode blocks DB according to the one horizontal line inthe display operation period Pd. In a touch detection operation periodPt, the drive electrode driver 14 sequentially applies the drive signalVcomAC having a frequency higher than a frequency of the display drivevoltage VcomDC to the drive electrode block DB according to the touchdetection operation, thus sequentially selecting one detection block.The display unit 10 with a touch detection function performs a displayoperation in the display operation period Pd based on the signalssupplied from the gate driver 12, the source driver 13, and the driveelectrode driver 14. The display unit 10 with a touch detection functionperforms a touch detection operation in the touch detection operationperiod Pt based on the drive signal VcomAC supplied from the driveelectrode driver 14, and outputs the touch detection signal Vdet fromthe touch detection electrode TDL. The touch detection signal amplifier42 amplifies and outputs the touch detection signal Vdet. The A/Dconvertor 43 converts the analog signal output from the touch detectionsignal amplifier 42 into a digital signal at a timing synchronized withthe drive signal VcomAC. The signal processing unit 44 detects thepresence or absence of a touch performed on the touch detection device30 based on the output signal of the A/D convertor 43. When the presenceof a touch is detected by the signal processing unit 44, the coordinateextracting unit 45 calculates touch panel coordinates of the touch, andoutputs the touch panel coordinates as a signal output Vout.

Auxiliary Wiring

FIG. 16 is an explanatory diagram for explaining a positional relationbetween a pixel and an auxiliary wiring according to the presentembodiment. FIG. 17 and FIG. 18 are explanatory diagrams for explaininga relationship among drive electrodes, drive electrode pieces, slits,and auxiliary wirings according to the present embodiment.

As illustrated in FIG. 16 and FIG. 17, the drive electrode COML is apattern of a translucent conductive material, and includes a driveelectrode piece COMLa where the translucent conductive material isformed, and a slit COMSL where the translucent conductive material isnot formed. In one drive electrode COML, a plurality of drive electrodepieces COMLa are formed by at least one slit COMSL of the driveelectrode COML. More specifically, the slit COMSL in the drive electrodeCOML is arranged for each row of the pixels, thereby forming theplurality of drive electrode pieces COMLa each of which has a width ofone pixel in the column direction and extends in the row direction. Thedrive electrode pieces COMLa formed in one drive electrode COML areconnected to each other at both ends thereof. In addition to the slitCOMSL formed in the drive electrode COML, there is a slit COMSL, wherethe translucent conductive material is not formed, between adjacentdrive electrodes COML, and the slit COMSL, where the translucentconductive material is not formed, separates the adjacent driveelectrodes COML. As illustrated in FIG. 17, a plurality of auxiliarywirings ML are arranged for each drive electrode COML. In the exampleillustrated in FIG. 17, one auxiliary wiring ML is arranged for eachdrive electrode piece COMLa formed in each drive electrode COML. Thatis, one auxiliary wiring ML is arranged for each row of the pixels. Eachauxiliary wiring ML is formed along the slit COMSL in plan view. Asillustrated in FIG. 17, the potential supply wirings PL bundle the driveelectrodes COML for each drive electrode block DB and simultaneouslysupply the drive signal VcomAC to the auxiliary wirings ML.

The drive electrode COML may be a pattern of a translucent conductivematerial illustrated in FIG. 18. Each drive electrode COML illustratedin FIG. 18 has a width of one pixel in the column direction. In theexample illustrated in FIG. 18, there is no slit COMSL in the driveelectrodes COML. That is, in this example, one drive electrode pieceCOMLa illustrated in FIG. 16 corresponds to one drive electrode COMLillustrated in FIG. 18. There is a slit COMSL, where the translucentconductive material is not formed, between adjacent drive electrodesCOML, and the slit COMSL, where the translucent conductive material isnot formed, separates the adjacent drive electrodes COML. At least oneauxiliary wirings ML is arranged for each drive electrode COML. In theexample illustrate in FIG. 18, with respect to each drive electrodeCOML, one auxiliary wirings ML is formed along a slit COMSL betweenadjacent drive electrodes COML in plan view. In addition, as illustratedin FIG. 18, a terminal may be provided at a center portion of a shortside of the drive electrode COML, and the terminal of the driveelectrode COML may be coupled to the potential supply wirings PL. Thus,the drive signal VcomAC is supplied to the drive electrode COML directlyfrom the potential supply wirings PL aside from the auxiliary wiringsML. With this configuration, the drive signal VcomAC is supplied to thedrive electrode COML directly from the potential supply wirings PL,while the drive signal VcomAC is supplied to the drive electrode COMLvia the auxiliary wirings ML. As illustrated in FIG. 18, the potentialsupply wirings PL bundle the drive electrodes COML for each driveelectrode block DB and simultaneously supplies the drive signal VcomACto the auxiliary wirings ML. The potential supply wirings PL directlysupplies the drive signal VcomAC to the drive electrodes COML for eachdrive electrode block DB. The structure of the pattern of thetranslucent conductive material illustrated in FIG. 18 is simplified byrepeating the same pattern.

The auxiliary wirings ML illustrated in FIG. 16 to FIG. 18 are formed ofa metal material, for example, aluminum (Al), having an electricalresistance lower than that of the translucent conductive material of thedrive electrode COML. The auxiliary wiring ML is disposed so as toextend in the row direction for each row of the pixels Pix, totransverse the display area Ad by passing between the frames Gd and Gd.It is preferable that the auxiliary wiring ML is directly andelectrically coupled to the potential supply wiring PL. This structuremakes the couple resistance be reduced.

The touch drive signal VcomAC is affected by an electrical resistancebased on the sheet resistance and the length of the drive electrodeCOML. When the electrical resistance of the drive electrode COML is highand if the display area Ad is large, influence of a time constant on thetouch drive signal VcomAC causes waveform rounding to occur, which maycause noise resistance to be degraded and accuracy of touch detection tobe affected. If the semiconductor layer of the switching element Tr isformed of amorphous silicon, it takes longer time to charge for thepixels in the display operation period Pd as compared with polysilicon,and therefore the length of the touch detection operation period Pt maypossibly be reduced. The display device 1 with a touch detectionfunction according to the present embodiment includes the auxiliarywirings ML whose electrical resistance is lower than that of the driveelectrode COML. Therefore, in the display device 1 with a touchdetection function according to the present embodiment, the influence ofthe time constant exerted on the waveform of the touch drive signalVcomAC supplied to the drive electrodes COML can be suppressed by theauxiliary wirings ML. The display device 1 with a touch detectionfunction according to the present embodiment can increase a transmissionspeed of the touch drive signal VcomAC supplied to the drive electrodesCOML using the auxiliary wirings ML, thus reducing the touch detectionoperation period Pt. Consequently, the display device 1 with a touchdetection function according to the present embodiment allows theimprovement in the accuracy of the touch detection and the increase inthe display area Ad. However, for the conductivity, the metal materialforming the auxiliary wirings ML has a lower electrical resistance thanthe translucent conductive material such as ITO, but its light blockingeffect increases.

For the pixel Pix according to the present embodiment, as illustrated inFIG. 9, FIG. 10, and FIG. 16, in the display area Ad, one pixel Pixincludes a plurality of sub-pixels SPix that represent mutuallydifferent colors. Arbitrary pixels, which are adjacent to each other inthe row direction and in each of which the sub-pixels SPix forming onepixel Pix are arrayed in one column with k rows (k is a natural numberof 3 or more), have a pixel array in which arbitrary sub-pixels SPixrepresenting the same color, among the color regions 32R, 32G, and 32Bof the three colors of R, G, and B, are arrayed along the row direction.In such a pixel array, an area along the slit COMSL between adjacentpixels Pix in the column direction is an area in which the auxiliarywiring ML hardly affects an aperture ratio even if it passes through thesub-pixels SPix.

Therefore, as illustrated in FIG. 16, the auxiliary wiring ML isarranged in an area along the slit COMSL between adjacent pixels Pix inthe column direction, for each row of pixels Pix. Thus, the auxiliarywirings ML is provided in the area that is blocked by a light blockingmaterial such as a black matrix, and therefore the influence on theaperture ratio is suppressed. The auxiliary wiring ML is provided alongthe scan line GCL adjacent thereto in the column direction. Thepotential of the auxiliary wiring ML becomes the common potential in thedisplay operation period Pd, and a potential difference with the scanline GCL is produced. The potential difference between the auxiliarywiring ML and the scan line GCL affects the orientation of liquidcrystal molecules, which causes burn-in or the like.

For this reason, the display device 1 with a touch detection functionaccording to the present embodiment uses the following structure toprevent the burn-in of the liquid crystal layer caused by the auxiliarywirings ML. FIG. 19 is a schematic diagram of a cross sectionschematically illustrating an A-B cross section of the pixel substrateillustrated in FIG. 16. FIG. 20 is a schematic diagram of a crosssection schematically illustrating a C-D cross section of the pixelsubstrate illustrated in FIG. 16. The translucent substrate 21 functionsas a TFT substrate on which various circuits are formed. The pixelelectrodes 22 arranged in the matrix and the drive electrode piecesCOMLa are formed on the translucent substrate 21. As illustrated in FIG.19, the pixel electrodes 22 and the drive electrode pieces COMLa areinsulated from each other by the insulating layer 24, and face eachother in the direction perpendicular to the surface of the translucentsubstrate 21. The pixel electrodes 22 and the drive electrode piecesCOMLa are translucent electrodes formed of a translucent conductivematerial (translucent conductive oxide) such as ITO.

A semiconductor layer 90 being the switching element Tr of each of thesub-pixels SPix, and wirings such as the data line SGL for supplying apixel signal to each of the pixel electrodes 22, and the scan line GCLfor driving each of the switching elements Tr are layered on the surfaceof the translucent substrate 21 through the insulating layer 24. Theauxiliary wiring ML is a wiring for supplying the potential of thepotential supply wiring PL to the drive electrode piece COMLa via athrough hole SH2. In the through hole SH2, the drive electrode pieceCOMLa is electrically coupled to the auxiliary wirings ML at aconnecting portion MLa. The through hole SH2 is provided to each pixel.Accordingly, there are a plurality of connecting portion MLa arrayedalong the auxiliary wirings ML in plan view. The drive electrode pieceCOMLa is supplied with a potential of the potential supply wiring PL viathe plurality of connecting portion MLa arrayed in the row direction.

The insulating layer 24 has an insulating layer (first insulating film)24 a between the scan line GCL and the semiconductor layer 90 and aninsulating layer (second insulating film) 24 b between the pixelelectrodes 22 and the drive electrode pieces COMLa, which are layered.More specifically, the insulating layer 24 a is layered on a location(layer) where each portion is in contact with the translucent substrate21 or with the scan line GCL. The insulating layer 24 b is layered on alocation (layer) where each portion is in contact with the data lineSGL, the semiconductor layer 90, or with the surface of the insulatinglayer 24 a. The insulating layer 24 a and the insulating layer 24 baccording to the present embodiment are inorganic insulating layer ofsilicon nitride (SiNx) or silicon oxide. The insulating layer 24 b maybe formed of an organic insulating material such as a polyimide resin.The material forming the layers of the insulating layer 24 a and theinsulating layer 24 b is not limited thereto. The insulating layers 24 aand 24 b may be formed of the same insulating material, or either one ofthem may be formed of a different insulating material.

As illustrated in FIG. 16 and FIG. 19, the scan line GCLthree-dimensionally intersects with part of the semiconductor layer 90to act as a gate GCLa of the switching element Tr. There is one portionat which the scan line GCL and part of the semiconductor layer 90three-dimensionally intersect with each other, and the switching elementTr is a single gate transistor with an n-channel region ch. Theswitching element Tr may be a double gate transistor, or any functionalelement (switching element) as long as it has a switching function. Thesemiconductor layer 90 is formed of, for example, amorphous silicon. Thedata line SGL extends on a plane parallel to the surface of thetranslucent substrate 21, and supplies a pixel signal for displaying animage to pixels. The semiconductor layer 90 is in contact with a sourceSGLa coupled at part thereof to the data line SGL, and is electricallycoupled at the other portion to a drain SGLb formed on the same layer asthe data line SGL. The drain SGLb according to the present embodimentelectrically coupled to the pixel electrode 22 by a through hole SH1. Inthe present embodiment, the scan line GCL is a wiring of metal such asmolybdenum (Mo) and aluminum (Al), and the data line SGL is a wiring ofmetal such as aluminum. The auxiliary wiring ML is a wiring of metalsuch as aluminum. The auxiliary wiring ML, the scan line GCL and thedrive electrode piece COMLa, the insulating layer 24 a, the data lineSGL and the semiconductor layer 90, the insulating layer 24 b, and thepixel electrodes 22 are layered on the translucent substrate 21according to the present embodiment in this order.

Openings SL are formed with respect to the pixel electrodes 22corresponding to the sub-pixels SPix, and the liquid crystal is drivenby an electric field (fringe electric field) leaked from the openings SLin the pixel electrodes 22 of the electric field formed between thedrive electrode piece COMLa and the pixel electrodes 22.

The auxiliary wiring ML is a wiring for supplying a potential of thepotential supply wiring PL to the drive electrode piece COMLa via thethrough hole SH2, and electrically couples to the drive electrode pieceCOMLa via the through hole SH2, which enables the display drive voltageVcomDC to be supplied to the sub-pixels SPix.

As illustrated in FIG. 20, the auxiliary wiring ML is provided along thescan line GCL adjacent thereto in the column direction. The potential ofthe auxiliary wiring ML becomes a common potential in the displayoperation period Pd, and a potential difference between the auxiliarywiring and the scan line GCL is produced. However, the scan line GCLadjacent to the slit COMSL overlaps with the drive electrode piece COMLain the vertical direction of the translucent substrate 21. The scan lineGCL is covered with the drive electrode piece COMLa having the samepotential as that of the auxiliary wiring ML and shielded, and thereforethe influence of the potential difference on the liquid crystal layercan be reduced. The auxiliary wiring ML overlaps with the driveelectrode piece COMLa in the vertical direction of the translucentsubstrate 21. With this structure, the electric field due to thepotential difference between the voltage of the drive electrode COML andthe voltage of the pixel electrode 22 hardly reaches the liquid crystallayer. Therefore, as illustrated in FIG. 16, a width CP of the driveelectrode piece COMLa in the column direction with respect to one pixelPix according to the present embodiment becomes wider than a maximumdistance PP in the column direction between the auxiliary wiring ML andthe scan line GCL with respect to the one pixel Pix. With thisstructure, the potential difference between the auxiliary wiring ML andthe scan line GCL hardly affects the orientation of the liquid crystalmolecules, thus reducing the possibility of the burn-in or so.

FIG. 21 and FIG. 22 are explanatory diagrams representing a pixel arrayaccording to modifications of the present embodiment. In the aboveexample, the color filter illustrated in FIG. 8 is configured toperiodically array the color regions of the color filter respectivelycolored in the three colors of, for example, red (R), green (G), andblue (B), and to associate the color regions 32R, 32G, and 32B of thethree colors of R, G, and B, which are grouped in a set as a pixel Pix,with the sub-pixels SPix illustrated in FIG. 10. The present embodimentis not limited thereto. As illustrated in FIG. 21, color regions of thecolor filter respectively colored in four colors of, for example, red(R), green (G), blue (B), and white (W) are periodically arrayed in thecolumn direction, and color regions 32R, 32G, 32B, and 32W of the fourcolors of R, G, B, and W, which are grouped in a set as a pixel Pix, maybe associated with the sub-pixels SPix illustrated in FIG. 10. Asillustrated in FIG. 22, color regions of the color filter respectivelycolored in four colors of, for example, red (R), green (G), blue (B),and yellow (Y) are periodically arrayed in the column direction, andcolor regions 32R, 32G, 32B, and 32Y of the four colors of R, G, B, andY, which are grouped in a set as a pixel Pix, may be associated with thesub-pixels SPix illustrated in FIG. 10.

As explained above, the display device 1 with a touch detection functionaccording to the present embodiment and the modifications includes thedisplay area Ad, the display function layer exemplified as the liquidcrystal layer, the pixel electrode 22, the scan line GCL, the data lineSGL, the drive electrode COML (drive electrode piece COMLa), theauxiliary wiring ML, the touch detection electrode TDL, the controldevice, and the touch detection unit 40.

The display area Ad has a plurality of pixels arranged in a matrixincluding a plurality of rows and a plurality of columns, and one pixelincludes a plurality of sub-pixels for representing mutually differentcolors. In arbitrary pixels which are adjacent to each other and in eachof which the sub-pixels are arrayed in one column with k rows, arbitrarysub-pixels representing the same color are arrayed along the rowdirection. A plurality of scan lines GCL extend in the row direction ofthe display area Ad, and scan the switching elements of the sub-pixels.A plurality of data lines SGL extend in the column direction of thedisplay area Ad, and supply an applied voltage to the pixel electrodes.With this structure, the number of data lines SGL can be reduced, and acircuit scale of the source driver 13 can be decreased.

The display function layer has only to have the image display functionfor displaying an image in the display area, and may be an organicelectro-luminescence (OEL) layer instead of the liquid crystal layer.

The pixel electrode 22 is provided in each of the sub-pixels SPix, andprovides an applied voltage to the display function layer by a potentialdifference with the common potential which is a reference. The driveelectrode COML is provided facing the pixel electrode 22, and extends inthe row direction. The shape that extends in the column direction or inthe row direction may be bent depending on the pattern as illustrated inFIG. 16.

The auxiliary wiring ML is a wiring of a metal material having anelectrical resistance lower than that of a material of the driveelectrode COML. The auxiliary wiring ML is arranged so as to extend inthe row direction for each row of a pixel Pix, and is electricallycoupled to the drive electrode COML via the through hole SH2.

The display device 1 with a touch detection function according to thepresent embodiment and the modifications performs image display controlso that the control device applies a common potential between the pixelelectrode 22 and the drive electrode COML in the display operationperiod Pd based on the image signal and achieves the image displayfunction of the display function layer. Moreover, the display device 1with a touch detection function according to the present embodiment andthe modifications performs touch detection control so that the controldevice time-divisionally and sequentially supplies the touch drivesignal VcomAC to the drive electrodes COML in the touch detectionoperation period Pt for each drive electrode block DB. The touchdetection electrode TDL faces the drive electrode COML to form acapacitance with the drive electrode COML. The touch detection unit 40detects a position of a proximity object based on the detection signalfrom the touch detection electrode TDL in the touch detection operationperiod Pt.

Thereby, the influence of the auxiliary wiring ML on the aperture ratiois suppressed. The auxiliary wiring ML applies the touch drive signalVcomAC to the drive electrode piece COMLa, which enables the operationin the touch detection operation period Pt to be performed while theinfluence of the time constant on the touch drive signal VcomAC issuppressed. Consequently, the waveform of the touch drive signal VcomACis transmitted satisfactorily, thus improving the detection accuracy(touch detection accuracy) of the proximity object.

Although the semiconductor of the switching element Tr according to thepresent embodiment is formed of amorphous silicon, the material of theauxiliary wiring ML has a lower resistance than that of the driveelectrode COML, and therefore the time required for transmitting thetouch drive signal VcomAC for each drive electrode block DB can beensured in the touch detection operation period Pt.

The drive electrode COML according to the present embodiment has theslit COMSL that extends in the row direction of the display area and isprovided in a boundary area of pixels Pix adjacent to each other in thecolumn direction of the display area Ad. The slits COMSL arranged at agiven pitch are hard to be recognized, and this enables the potential ofthe potential supply wiring PL supplied for each auxiliary wiring ML tobe stabilized in the row direction.

The scan line GCL adjacent to the slit COMSL overlaps with the driveelectrode COML in the vertical direction of the pixel substrate 2. Withthis structure, the scan line GCL is shielded by a conductor having thesame potential as that of the auxiliary wiring ML.

The auxiliary wiring ML overlaps with the drive electrode COML in thevertical direction of the pixel substrate 2. Therefore, the electricfield in association with the potential difference between the scan lineGCL adjacent to the slit COMSL and the auxiliary wiring ML is preventedfrom being leaked to the liquid crystal layer.

The auxiliary wirings ML are electrically coupled to the driveelectrodes COML via the through holes SH2 respectively arranged in thepixels Pix that are arrayed in the row direction of the display area Ad.With this structure, the fluctuation of the common potential in thedisplay area Ad can be suppressed in the display operation period Pd.Accordingly, the display device 1 with a touch detection functionaccording to the present embodiment and the modifications can keepdisplay quality even in a central portion of the display area Ad in thedisplay operation period Pd.

Application Examples

Application examples of the display device 1 with a touch detectionfunction as explained in the present embodiment will be explained nextwith reference to FIG. 23, FIG. 24, and FIG. 25. FIG. 23, FIG. 24, andFIG. 25 are diagrams of examples of an electronic apparatus to which thedisplay device with a touch detection function according to the presentembodiment is applied. The display device 1 with a touch detectionfunction according to the present embodiment can be applied toelectronic apparatuses in all fields such as television devices, adigital camera illustrated in FIG. 23 and FIG. 24, notebook personalcomputers, portable electronic apparatuses such as a mobile telephone,car-mounted electronic apparatuses such as a car navigation systemillustrated in FIG. 25, or video cameras. In other words, the displaydevice 1 with a touch detection function according to the presentembodiment can be applied to electronic apparatuses in all fields thatdisplay an externally input video signal or an internally generatedvideo signal as an image or a video. The electronic apparatus includes acontrol device that supplies a video signal to a liquid-crystal displaydevice and controls the operation of the liquid-crystal display device.

The electronic apparatus illustrated in FIG. 23 and FIG. 24 is a digitalcamera to which the display device 1 with a touch detection functionaccording to the present embodiment is applied. The digital cameraincludes, for example, a light emitting unit 521 for a flash, a displayunit 522, a menu switch 523, and a shutter button 524. The display unit522 is the display device with a touch detection function according tothe present embodiment.

The electronic apparatus illustrated in FIG. 25 is a car navigationdevice to which the display device 1 with a touch detection functionaccording to the present embodiment is applied. The display device 1with a touch detection function is installed in a dashboard 300 inside avehicle. Specifically, it is installed between a driver's seat 311 and apassenger's seat 312 in the dashboard 300. The display device 1 with atouch detection function of the car navigation device is used fordisplay of navigation, display of a music operation screen, or displayof movie reproduction, and the like.

The embodiment is not limited by the contents described above. Inaddition, the components of the embodiment include those which can beeasily thought of by persons skilled in the art, those which aresubstantially equivalent to each other, and those in a scope ofso-called equivalents. Moreover, the components can be omitted,replaced, and modified in various ways within a scape that does notdepart from the gist of the embodiment.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention claimed is:
 1. A display device with a touch detectionfunction comprising: a display area that has a plurality of pixelsarranged in a matrix including a plurality of rows and a plurality ofcolumns, in which one of the pixels includes a plurality of sub-pixelsthat represent mutually different colors and are arrayed in one columnwith k rows (k is a natural number of 3 or more), and in which arbitrarysub-pixels representing same color among arbitrary pixels that areadjacent to each other in a row direction are arrayed along the rowdirection; a display function layer that has an image display functionfor displaying an image in the display area; a pixel electrode that isprovided in each of the sub-pixels and supplies an applied voltage tothe display function layer by a potential difference with a commonpotential which is a reference; a plurality of scan lines that extend inthe row direction of the display area and scan switching elements of thesub-pixels; a plurality of data lines that extend in a column directionof the display area and supply an applied voltage to the pixelelectrodes; a plurality of drive electrodes that are provided facing thepixel electrodes and extend in the row direction; a slit that extendsbetween the drive electrodes in the row direction of the display area,and the slit is provided in a boundary area of the pixels adjacent toeach other in the column direction of the display area; an auxiliarywiring that is a wiring of a metal material having an electricalresistance lower than that of a material of the drive electrodes, theauxiliary wiring being arranged along the slit so as to extend in therow direction for each row of the sub-pixels representing the same colorand being electrically coupled to a drive electrode, and the auxiliarywiring overlaps with the drive electrode in a vertical direction of apixel substrate; a control device that performs image display control soas to apply the common potential to the drive electrodes based on animage signal to achieve the image display function of the displayfunction layer, and that performs touch detection control so as tosupply a drive signal for touch to the drive electrodes; a touchdetection electrode that faces the drive electrodes and forms acapacitance with the drive electrodes; and a touch detection unit thatdetects a position of a proximity object based on a detection signalsent from the touch detection electrode.
 2. The display device with atouch detection function according to claim 1, wherein a semiconductorof the switching element is formed of amorphous silicon.
 3. The displaydevice with a touch detection function according to claim 1, wherein atleast one of the scan lines adjacent to the slit in the column directionoverlaps with the drive electrode in the vertical direction of the pixelsubstrate.
 4. The display device with a touch detection functionaccording to claim 3, wherein a width of respective drive electrode inthe column direction of the display area with respect to one of thepixels is wider than a maximum distance between the auxiliary wiring anda scan line with respect to the one of the pixels in the columndirection of the display area, and wherein the scan line overlaps withthe respective drive electrode.
 5. The display device with a touchdetection function according to claim 1, wherein the auxiliary wiring iselectrically coupled to the drive electrode via a through hole arrangedin each of the pixels which are arrayed in the row direction of thedisplay area.
 6. An electronic apparatus that includes the displaydevice with a touch detection function according to claim 1.